| // *************************************************************************************************************************** |
| // * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file * |
| // * distributed with this work for additional information regarding copyright ownership. The ASF licenses this file * |
| // * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance * |
| // * with the License. You may obtain a copy of the License at * |
| // * * |
| // * http://www.apache.org/licenses/LICENSE-2.0 * |
| // * * |
| // * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an * |
| // * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the * |
| // * specific language governing permissions and limitations under the License. * |
| // *************************************************************************************************************************** |
| package org.apache.juneau.http; |
| |
| import static org.apache.juneau.internal.StringUtils.*; |
| |
| import org.apache.juneau.http.annotation.*; |
| import org.apache.juneau.internal.*; |
| |
| /** |
| * Represents a parsed <l>If-Range</l> HTTP request header. |
| * |
| * <p> |
| * If the entity is unchanged, send me the part(s) that I am missing; otherwise, send me the entire new entity. |
| * |
| * <h5 class='figure'>Example</h5> |
| * <p class='bcode w800'> |
| * If-Range: "737060cd8c284d8af7ad3082f209582d" |
| * </p> |
| * |
| * <h5 class='topic'>RFC2616 Specification</h5> |
| * |
| * If a client has a partial copy of an entity in its cache, and wishes to have an up-to-date copy of the entire entity |
| * in its cache, it could use the Range request-header with a conditional GET (using either or both of |
| * If-Unmodified-Since and If-Match.) |
| * However, if the condition fails because the entity has been modified, the client would then have to make a second |
| * request to obtain the entire current entity-body. |
| * |
| * <p> |
| * The If-Range header allows a client to "short-circuit" the second request. |
| * Informally, its meaning is `if the entity is unchanged, send me the part(s) that I am missing; otherwise, send me |
| * the entire new entity'. |
| * <p class='bcode w800'> |
| * If-Range = "If-Range" ":" ( entity-tag | HTTP-date ) |
| * </p> |
| * |
| * <p> |
| * If the client has no entity tag for an entity, but does have a Last- Modified date, it MAY use that date in an |
| * If-Range header. |
| * (The server can distinguish between a valid HTTP-date and any form of entity-tag by examining no more than two |
| * characters.) |
| * The If-Range header SHOULD only be used together with a Range header, and MUST be ignored if the request does not |
| * include a Range header, or if the server does not support the sub-range operation. |
| * |
| * <p> |
| * If the entity tag given in the If-Range header matches the current entity tag for the entity, then the server SHOULD |
| * provide the specified sub-range of the entity using a 206 (Partial content) response. |
| * If the entity tag does not match, then the server SHOULD return the entire entity using a 200 (OK) response. |
| * |
| * <ul class='seealso'> |
| * <li class='extlink'>{@doc RFC2616} |
| * </ul> |
| */ |
| @Header("If-Range") |
| public final class IfRange extends HeaderString { |
| |
| /** |
| * Returns a parsed <c>If-Range</c> header. |
| * |
| * @param value The <c>If-Range</c> header string. |
| * @return The parsed <c>If-Range</c> header, or <jk>null</jk> if the string was null. |
| */ |
| public static IfRange forString(String value) { |
| if (value == null) |
| return null; |
| return new IfRange(value); |
| } |
| |
| private IfRange(String value) { |
| super(value); |
| } |
| |
| /** |
| * Returns this header value as a {@link java.util.Date} object. |
| * |
| * @return This header value as a {@link java.util.Date} object, or <jk>null</jk> if the value is not a date. |
| */ |
| public java.util.Date asDate() { |
| char c0 = charAt(value, 0), c1 = charAt(value, 1); |
| if (c0 == '*' || c0 == '"' || (c0 == 'W' && c1 == '/')) |
| return null; |
| return DateUtils.parseDate(toString()); |
| } |
| |
| /** |
| * Returns this header value as an {@link EntityValidator} object. |
| * |
| * @return |
| * This header value as a {@link EntityValidator} object, or <jk>null</jk> if the value is not an entity |
| * validator. |
| */ |
| public EntityValidator asValidator() { |
| char c0 = charAt(value, 0), c1 = charAt(value, 1); |
| if (c0 == '*' || c0 == '"' || (c0 == 'W' && c1 == '/')) |
| return new EntityValidator(value); |
| return null; |
| } |
| } |